1. Field of the Invention
The invention relates to an injection nozzle, having a nozzle body, a nozzle needle that is supported displaceably in the nozzle body, a control chamber that is in communication with a fluid inlet line and a fluid outlet line, and a control element that can open and close the fluid outlet line.
2. Description of the Prior Art
From the prior art, injection nozzles of the above type are known that are used in common rail injection systems. For closing the needle, they have a closing spring, which is located in the control chamber. The size of the spring thus determines the control chamber volume. Since for good closure of the needle, the spring should have the greatest possible stiffness and is thus relatively large, the control chamber volume also becomes comparatively great. This makes the injector sluggish, and the quantity and instant of injection cannot be defined exactly.
One object of the invention is therefore to refine an injection nozzle of the type defined at the outset in such a way that the dimensions of the closing spring can be selected freely, independently of the control chamber volume and independently of the control piston diameter that is important for the needle speed. Another object of the invention is for the nozzle needle guide no longer to have to assume any sealing function.